Classifications

• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
  • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
  • G06F3/016—Input arrangements with force or tactile feedback as computer generated output to the user
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
  • B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
  • B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
  • B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
  • B06B1/0207—Driving circuits
  • B06B1/0223—Driving circuits for generating signals continuous in time
  • B06B1/0269—Driving circuits for generating signals continuous in time for generating multiple frequencies
  • B06B1/0276—Driving circuits for generating signals continuous in time for generating multiple frequencies with simultaneous generation, e.g. with modulation, harmonics
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
  • B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
  • B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
  • B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
  • B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
  • B06B1/0607—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements
  • B06B1/0622—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements on one surface
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
  • B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
  • B06B2201/00—Indexing scheme associated with B06B1/0207 for details covered by B06B1/0207 but not provided for in any of its subgroups
  • B06B2201/50—Application to a particular transducer type
  • B06B2201/55—Piezoelectric transducer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
  • B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
  • B06B2201/00—Indexing scheme associated with B06B1/0207 for details covered by B06B1/0207 but not provided for in any of its subgroups
  • B06B2201/70—Specific application
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
  • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
  • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
  • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means

Definitions

• the present invention relates to the field of tactile interfaces using several electromechanical actuators, in particular piezoelectric, distributed over the interface.
• each piezoelectric actuator must be supplied with electrical energy in order to be able to transform it into a deformation thanks to the piezoelectric effect.
• the energy must therefore be distributed in a complex manner over the whole of the vibrating structure, which generates complexity in the supply architecture of the actuators.
• the various actuators are supplied 0 in parallel. They are then supplied by the same electric voltage, but this does not guarantee the synchronization of the movements of the actuators, and therefore the good coordination of the actions on the touchscreen interface, because each actuator can have its own resonant frequency.
• the actions of the various actuators must be well coordinated in order to produce a good tactile sensation for a user, which generates a complexity of the control architecture of the actuators.
• each actuator has its own amplifier and the voltage reference comes from a single computer.
• This 0 method allows the synchronization of actions via this single computer.
• it is complex to implement because the single computer must include multiple outputs.
• the single controller DSP
• the single controller For the signal and the power of the actuators.
• the single controller then needs several inputs for the measurement of the deformations, and several outputs for supply voltages.
• the single controller must therefore include a large number of inputs / outputs, which makes it complex and expensive.
• the distribution of the power supply to the various actuators is often at high voltage, and therefore risks generating a crosstalk phenomenon, that is to say that the power supply an actuator can disturb the power supply to neighboring actuators, and the overall vibratory effect is disturbed. It can also disturb the vibration measurements, and therefore the supply voltage of an actuator can be found in the vibration measurement of a sensor of the system.
• the known architectures with multiple actuators are often very sensitive to changes in environmental conditions, such as the operating temperature, and the tactile effect obtained using the actuators can be disturbed.
• the general aim of the invention is to propose a new type of sensor-actuator for ultrasonic applications, making it possible to solve the problems mentioned above and the drawbacks of known systems with multiple actuators.
• the particular object of the invention is to provide a unitary actuator sensor, and a system using such actuator sensors, in which the energy conversion (that is to say the supply to the actuators) is carried out at the level of each actuator, so that energy is distributed to each actuator and not voltage, in order to generate less crosstalk between actuators.
• Another particular object of the invention is to propose a system of several sensors - actuators to which the vibratory references are supplied by a communication link from a master microcontroller, and this at a reduced frequency.
• the present invention proposes a distributed and hierarchical vibration control structure comprising a master and a set of slaves.
• a slave is a unit sensor-actuator couple in which the sensor and the actuator are co-located, that is to say located ideally at the same place of a plate to be actuated, or at least at a very short distance one on the other on the plate. Its role is to locally control the vibration of the plate.
• the sensor-actuator pair comprises a DC-AC converter to supply the actuator by amplifying the signals from the control circuit using the measurements from the sensor. It acts locally and quickly to follow the instructions assigned to it by the master processor.
• a slave is therefore a sensor-actuator system integrating:
• the “master” controller or processor sends the local vibratory references of the plate to each sensor-actuator, determined from the reference to be made globally. It receives quantities (measurements, voltages) from the unit sensor-actuators. By aggregating this information, the master has overall information and can adjust the references transmitted to each of the slaves.
• the subject of the invention is therefore a unitary sensor-actuator, intended to be fixed on a first face of a plate to be actuated according to at least one predetermined vibratory mode of the plate, said unitary sensor-actuator comprising an electromechanical actuator and a sensor deformation or vibratory speed both fixed on said first face of the plate so as to create on a second face of the plate opposite said first face a vibration generating a haptic effect perceptible by a finger or a stylus of a user, characterized in that the actuator and the sensor are fixed side by side on said first face and are separated by a distance less than or equal to half the wavelength of the vibration at the lowest resonant frequency at which the actuator must actuate said plate, so that the actuator and the sensor can respectively actuate and measure a same predetermined vibratory mode of the plate. In this way, it is avoided that a given sensor-actuator can measure vibratory modes that it is not able to actuate.
• the distance between the sensor and the actuator is less than or equal to the half wavelength of the vibration at the lowest resonant frequency at which the actuator must actuate said plate.
• the distance between the sensor and the actuator is equal to a multiple of the half wavelength of the vibration.
• the electromechanical actuator is a piezoelectric actuator.
• the maximum size of the actuator (namely its length in the case of a rectangular actuator) is between 2 and 25 mm, so as to ensure the actuation and measurement functions while being small enough to be able to excite the vibratory modes of the smallest wavelengths in an ultrasonic vibratory frequency range between 20 kHz and 200 kHz.
• the senor is arranged to supply a measurement signal w (t) to a processor associated with the sensor-actuator, and said processor is arranged to calculate the instantaneous value noted Vin (t) of the supply voltage to be delivered to the actuator.
• the sensor-actuator comprises a DC to AC voltage converter controlled by the processor associated with the sensor-actuator.
• the value of the supply voltage Vin (t) is slaved by a digital controller to the instantaneous value of the measurement signal w (t) delivered by the sensor.
• the subject of the invention is also a tactile device comprising a vibrating plate, characterized in that it comprises a set of unit sensor-actuators as described above, distributed and fixed on one face of a vibrating plate.
• this tactile device comprises a master processor connected in parallel to an input of each of the slave processors of the unit sensor-actuators, so as to be able to dissociate the control signals from the different actuators.
• the master processor is configured to send to each slave processor synchronization information at a frequency lower than the vibration frequency of the sensors.
• the master processor is configured to execute during an initialization phase an auto-addressing algorithm so as to automatically map the sensor-actuator network on the plate to be actuated.
• the master processor is configured to transmit to the slave processors working parameters, namely the data necessary for the control of one or more vibratory mode (s) of the plate to be actuated. It can also be configured to transmit to the slave processors voltage setpoints for each vibratory mode, depending on the spatial distribution of the sensor-actuators, the resonance frequencies assigned to the different sensor-actuators during the initialization phase, and depending on the desired effect for a user on a tactile face of the plate to be actuated.
• the master processor is configured to, during a diagnostic phase, interrogate the slave processors to obtain their operating parameters and to correct the parameterization of the individual sensor-actuators if necessary.
• the master processor is configured to, during an interfacing phase, communicate to an external processing device the data collected from the slave processors in order to allow their post-processing.
• FIG. 1 represents a simplified diagram of an experimental device of the same inventors, described in the document (2) of the state of the art cited above;
• FIG. 2 represents a diagram of the architecture of a unit sensor-actuator assembly according to the invention.
• FIG. 3 represents the internal diagram of the processor which controls each of the sensor-actuators
• FIG. 4 represents the principle of controlling the vibration using a rotating marker
• FIG. 5 represents the electric power supply circuit of various piezoelectric actuators
• FIG. 6 represents a diagram of the architecture of a plurality of sensor-actuators in accordance with the invention for actuating a tactile interface.
• FIG. 1 schematically illustrating the experimental device known from document (2) cited above and using a single actuator of the Langevin type, constituted by a piezoelectric pellet interposed between a vibrating mass provided with a textured upper surface , and a foreman.
• a piezoelectric vibration sensor is fixed directly on the Langevin actuator, namely on its vibrating mass, and not on a plate carrying a Langevin type actuator.
• a user can test the tactile effect generated directly on the actuator by placing a finger on the textured top surface of its vibrating mass.
• An actuator-sensor 1 comprises an electromechanical actuator 2 (of the piezoelectric or electromechanical or other type) and a deformation or vibratory speed sensor 3 (of the same type as the examples cited above for example) both fixed on said first face 4a of the plate 4 so as to create on a second face 4b of the plate 4 opposite to said first face 4a a vibration generating a haptic effect perceptible by a finger or a stylus of a user placed on the second face 4b of the plate.
• electromechanical actuator 2 of the piezoelectric or electromechanical or other type
• a deformation or vibratory speed sensor 3 of the same type as the examples cited above for example
• the actuator 2 and the sensor 3 are co-located on a face 4a of a vibrating plate 4, that is to say that the measurement by the sensor 3 is very close to the place where s' applies the actuation by the actuator 2.
• plate in the context of the present invention, is meant a sheet of any material, rigid, solid, and of small thickness compared to its other dimensions.
• the distance between the sensor 3 and the actuator 2 is less than the half wavelength of the vibration according to the lowest resonant frequency at which the actuator must actuate said plate 4.
• This sensor-actuator assembly 1 is attached to a vibrating structure, shown here in the form of a vibrating plate or slab 4.
• the sensor 3 and the actuator 2 are attached to a face 4a of the plate 4, for example. by gluing.
• the size of the sensor-actuator assembly 1 must be large enough to perform the actuation and measurement functions, but small enough to be able to excite the small wavelength vibration modes.
• the maximum size of the actuator 2 (namely its length in the case of a rectangular actuator) is between 2 and 25 mm, so as to ensure the actuation and measurement functions while being small enough to be able to excite the vibratory modes of high frequency and therefore of small wavelength.
• Each sensor-actuator 1 of the device is controlled by a digital signal processor 5 (also denoted DSP, acronym for “Digital Signal Processor” in English terminology) which receives as input the signal from the sensor 3 and delivers a signal as output control to a DC / AC voltage converter 6 in order to locally control the vibratory amplitude to a set value.
• DSP Digital Signal Processor
• the DSP processor 5 and the voltage converter 6 are also very close to the sensor 3 and the actuator 2. But in reality they should be at a certain distance because they should not interfere with the vibration of the vibrating plate 4.
• FIG. 3 represents the internal diagram of the DSP processor 5 which controls each of the sensor-actuators 1.
• the dotted line block represents a working loop at high frequency, for example the frequency of 1 MHz given by a clock 7. The rest of the blocks work at a lower frequency.
• W (t) is the measurement coming from the sensor 3. It is an alternating voltage a priori sinusoidal which can be analogous to the vibratory speed or to the displacement of the surface 4 in the vicinity of the actuator 2.
• the output voltage intended for to be delivered to a sensor-actuator 1 is denoted Vin (t). It is also sinusoidal alternating.
• V d and V q are transmitted to a modulator 11 (which is also called Reverse Rotation).
• the demodulation carrier is necessarily synchronous and has the same pulsation as the vibration, since the latter is generated from the voltage v (t).
• this time T will be equal to the period of vibration of the mode considered, therefore of the resonance frequency considered.
• the Ns most significant bits of the counter C serve as an address to a ROM memory containing the values of the sine function.
• the cosine values for the same instant. Changes in vibration frequency are made by changing the value of DQ.
• each sensor-actuator 1 also has an electric power supply 13, capable of amplifying the voltage Vin, while ensuring the impedance matching.
• a bridge arm like the one shown schematically in Figure 5 can be used.
• a bus voltage denoted HV is cut by the method of pulse width modulation by two transistors 14.
• An inductor 15 filters the harmonic content while ensuring the alternation of the sources.
• the piezoelectric actuator is capacitive. If you connect it to a voltage source, it generates huge transient currents. To avoid this, we arrange to insert a current source, to comply with the rule of alternation of sources as known in power electronics.
• closed loop control of the voltage can be implemented at the level of the DSP processor 5 of each unitary sensor-actuator 1.
• FIG. 6 represents a diagram of a system 16 using a plurality of unitary sensor-actuators 1 as described above, which makes it possible to supply and control a set of electromechanical actuators distributed over a resonator, for example a tactile interface 4.
• the device 16 is hierarchical as shown in FIG. 6. It comprises a main processor 17 which plays the role of master coordinating the processors 5 of the various unit sensor-actuators 1 which play the role of slave processors.
• the master processor 17 has suitable calculation capacities, but it is not necessarily very fast, and does not require specialized peripherals. Its cost is therefore limited.
• the number of 1 slave sensor-actuators is variable. This number is determined by the user as a function of the plate 4 to be actuated and the vibratory modes to be controlled.
• Communication between the different elements is ensured via a network communication 18 on one or two wires (of the I2C or SPI type for example).
• Communication between master processor 17 and slave processors 5 can be relatively slow compared to a single processor structure conforming to the state of. the technique. It is used for administration operations with low bandwidth requirements such as structuring the sensor-actuator network 1, assigning slave processors 5, transmitting setpoints, synchronization, system diagnostics, or interfacing to external devices (not shown). These operations are described in more detail below.
• the master processor 17 executes an auto-addressing algorithm by which it automatically maps the sensor-actuator network 1.
• the master processor 17 transmits the working parameters to the slave processors 5 (specifically the data necessary for the control of one or more vibratory mode (s), such as the resonant frequency (s), damping (s), gains, parameters of the controller (s)).
• the references for each mode are calculated according to the spatial distribution of displacement, speed or acceleration necessary for the desired effect on the surface 4 to be actuated (vibration control, focusing ).
• the references expressed in the rotating frame described above (FIG. 4), correspond to the envelopes of the real trajectories.
• the envelope of a sinusoidal signal represents for example the evolution of the peak amplitude over time. As the evolution of the amplitude is slower than the sinusoidal signal, less points are needed per second to describe it, than for the signal itself.
• Synchronization for focused vibration type applications, the phase shifts between the different modulations are critical.
• Diagnosis on interrogation of the master processor 17, a slave processor 5 sends back to the master processor the elements necessary (voltages V d , V q , speed U d U q for example) for an operating diagnosis.
• the master processor 17 readjust the characteristics of the system, for example from an internal model of the structure. The readjustment makes it possible to adjust the dynamic parameters and possibly to rectify the parameter setting of the individual sensors-actuators 1 if necessary.
• the master processor 17 is capable of communicating with a more advanced device (computer, electronic tablet). This provides high-level tools to assist the user in the description phase of the structure to be actuated, the mapping of the arrangement of the sensors-actuators, the configuration of the internal model, namely a set of equations. which describe for example the modes of vibrations (modal strains). The parameters of these equations can be entered via the serial link.
• a more advanced device computer, electronic tablet
• the real instructions are transmitted by this means (the master processor 17 being then in charge of the projection in the modal base, that is to say that starting from a deformation of reference which one wishes, one calculates with from scalar product algorithms the amplitudes for each vibratory mode
• the master processor 17 can feed back the data collected from the slave processors 5 to allow their post-processing by the user.
• the invention meets the objectives set and makes it possible to solve the problems identified with actuators in accordance with the state of the art.
• each individual sensor-actuator 1 combined with a control by a master processor 17 makes it possible to simplify the connections and to share the electrical supply of the actuators (often high voltage) and the communication network, while avoiding inter-cable crosstalk.
• the synchronization of the unitary sensors-actuators 1 is ensured by the communication link and by the stability of the Quartz of the local processors 5.
• the unitary sensor-actuators 1 can be used in a network on several structures, the master processor 17 providing voltage references adapted to the application, which allows great versatility of use.
• Closed loop control allows adaptation to parametric variations due to changing environmental conditions, so device operation is robust.
• the problem of controlling the vibration that is not co-located with the sensor is that the relative phase between the actuation and the signal measured by the sensor changes depending on the mode.
• the actuator and the sensor can be in phase for one mode and in opposition for a neighboring mode. Therefore in closed loop, the stable loop for one mode can potentially be destabilized by the neighboring mode due to the sign change in the feedback.
• a sensor-actuator has a logical link which goes back to the master processor allows all the sensor-actuators to be synchronized.
• the master processor only needs low frequency communication with the slave processors which work locally at a higher frequency, which avoids having to oversize the master processor.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Theoretical Computer Science (AREA)
• Human Computer Interaction (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• User Interface Of Digital Computer (AREA)
• General Electrical Machinery Utilizing Piezoelectricity, Electrostriction Or Magnetostriction (AREA)
• Apparatuses For Generation Of Mechanical Vibrations (AREA)

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• 2019
  • 2019-02-27 FR FR1901994A patent/FR3093205B1/fr active Active
• 2020
  • 2020-02-27 WO PCT/FR2020/000048 patent/WO2020174134A1/fr active Search and Examination
  • 2020-02-27 KR KR1020217030861A patent/KR20210134352A/ko unknown
  • 2020-02-27 CN CN202080017247.8A patent/CN113454576A/zh active Pending
  • 2020-02-27 JP JP2021550126A patent/JP2022522705A/ja active Pending
  • 2020-02-27 US US17/434,229 patent/US11556180B2/en active Active
  • 2020-02-27 EP EP20721673.0A patent/EP3931670A1/fr active Pending

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